I am writing this whislt being ever so slightly frustrated with myself for being in a predicament:

After taking delivery of a new Bushido smart along with a set of X12 adapters I got it home and assembled the unit in aniticipation. When it came to mounting my roadbike I was disappointed to find the adapters I'd bought (T1709):
to convert X12 thru axles to fit the trainer didn't fit the bike.

Could any of you good people point me in the right direction of which ones to buy? A couple of photos showing the X12 thruaxle on the frame of my Cube Agree below. Many thanks for any help / guidance you can offer on this.

LPW wrote:Could any of you good people point me in the right direction of which ones to buy?

Not that it will resolve your issue but my first suggestion would be to remove that Shimano warning decal from the disc rotor!

I would think the circled adapters serve as end caps which are inserted over the ends of the thru-axle as depicted in the following image captured from the Tacx Dimensions of Tacx trainer axles pdf file:

I have tried the same adapters as you , T1709, and they didn't fit. The rod that should slide into the hollow axle end has a diameter that is too large. The other end cap has a lip that sinks into the groove on the frame. The problem is that the lip is 4.5mm and the groove is only 2mm therefore the cap is not secure and doesn't sit flush with the bike frame.

What finally WORKED for me is T1711 adapter from Tacx.
Was hard to find one online but fits the bike and the turbo trainer perfectly.
I would recommend this to all users trying to fit Cube road bikes with X-12 system onto a Tacx trainer.

Same problem here with the Cube Attain GTC sl disc 2017. I send an email to cube and they replied as follows:

thank you for your email.
Please notice, that all our carbon models are not allowed for bicycle trainer. Carbon frames can be seriously damaged by permanently fixing the bike on the bicycle trainer. Please see for further information the FAQ on our homepage.https://www.cube.eu/en/en/service/faq/

This is very strange because they support the professional Team Wanty Robert and there are plenty of photos showing the Wanty riders with a carbon Cube frame on a Tacx trainer. I thought the carbon on an indoor trainer discussion was closed years ago. Not really helpful from the Cube team.

I can confirm that T1711 perfectly fits the Cube Attain GTC Pro Disc 2016. I've replaced its Cube X12 axle with T1711 and it works perfectly with Tacx Booster. It didn't even require any tuning to gears or brake caliper.